三维时间飞跃法磁共振血管成像原始图像评估脑微出血病灶的应用价值

目的 研究三维时间飞跃法磁共振血管成像（three dimensional time-of-flight magnetic resonance angiography,3D-TOF MRA）原始图像评估脑内微出血病灶的应用价值。方法 收集269例高血压、缺血性卒中、短暂性脑缺血或既往原发性脑出血病患者。分别进行T2*加权梯度回波（T2* weighted gradient echo,T2*GRE）序列及3D-TOF MRA序列扫描,评估T2*GRE图像及3D-TOF MRA原始轴位图像显示的微出血病灶数量、部位及分级。结果 75例患者脑实质内存在微出血病灶,排除9例不符合标准者,剩余66例。T2*GRE成像共发现微出血病灶338个,1级50例,2级10例,3级6例;3D-TOF MRA序列原始图像显示微出血病灶242个,0级11例,1级40例,2级12例,3级3例。两种序列发现微出血病灶的比较差异有显著性（皮质和皮质下P=0.000、丘脑P=0.001、小脑P=0.039）;对基底节（P=0.581）和脑干（P=0.211）发现的微出血病灶之间的差异无显著性。结论 3D-TOF MRA原始图像可显示脑微出血灶。在无T2*GRE图像的情况下,观察3D-TOF MRA原始图像有助于了解及初步观察脑微出血情况

Application Value of Source Images by Three-Dimensional Time-of-Flight Magnetic Resonance Angiography in Detecting Cerebral Microbleeds

Objective To study the value of source images of three dimensional time-of-flight magnetic resonance angiography（3D-TOF MRA） in detecting cerebral microbleeds（CMBs） in brain parenchyma. Methods Two hundred and eighty patients who were suspected to have microbleeding lesions were recruited. T2＊ gradient recall echo（GRE） sequence and 3D-TOF MRA sequences were performed after routine magnetic resonance（MR） head imaging were performed. Numbers, location, and scales of CMBs on 3D-TOF MRA axial source images and T2＊GRE images were compared. Results Seven-five cases were proved to have CMBs by T2＊GRE sequence. Nine cases which could not be compared were excluded. On T2＊GRE images, three hundred and thirty eight CMBs were found with 50 cases as grade 1, 10 cases as grade 2, and 6 cases as grade 3. On 3D-TOF MRA source images, two hundred and forty two CMBs were found with 1 lcases as grade 0, 40 cases as grade 1, 12 cases as grade 2, and 3 cases as grade 3. Paired-sample t test showed that there were significant difference between CMBs found by two methods at cortical/subcortical area（P=0.000）, thalami（P=0.001）, and cerebellum（P=0.039）, while no significant difference were found between CMBs found by two methods at basal ganglia（P~0.581） and brain stem（P-0.211）. Consistency of two different sequences showed Kappa value was 0.494（P=0.092）. Conclusion Source images of 3D-TOF MRA can be used to detect CMBs. Though CMBs on 3D-TOF MRA source images were not as clear as those on T2＊GRE images, when T2＊GRE images are absent, 3D-TOF MRA source images may be helpful to display microbleeds lesions and suggest further examination.